A 2011 study found that a single dose of psilocybin could permanently increase the personality dimension of Openness To Experience. I’m emphasizing that because personality is otherwise pretty stable after adulthood; nothing should be able to do this. But magic mushrooms apparently have this effect, and not subtly either; participants who had a mystical experience on psilocybin had Openness increase up to half a standard deviation compared to placebo, and the change was stable sixteen months later. This is really scary. I mean, I like Openness To Experience, but something that can produce large, permanent personality changes is so far beyond anything else we have in psychiatry that it’s kind of terrifying.